arc-router

Arc Router enables instant cross-chain USDC transfers using Circle's Arc L1 as a liquidity hub. Users send USDC from any supported chain to any destination chain in under 10 seconds with a single click. By treating multiple blockchains as one unified liquidity surface, we eliminate the complexity of bridging, wrapped tokens, and multi-step transactions. The application leverages Arc's 1-2 second finality to settle transfers natively, providing a seamless experience that feels like traditional fintech payments while remaining fully decentralized.

Built with Next.js frontend, Node.js backend, and Circle Gateway API for cross-chain routing. Smart contracts on each chain lock and release USDC, while Arc L1 handles settlement. Used viem for EVM interactions, RainbowKit for wallet connection, and PostgreSQL for transaction tracking. The "hacky" part: optimistic UI updates that show "sent" instantly while Arc confirms in the background, creating perceived sub-second speed despite blockchain latency. Deployed on Vercel with Railway for API.